Related Experiment Videos
Patent foramen ovale as a possible risk factor for cryptogenic brain abscess: report of two cases
T Kawamata1, M Takeshita, N Ishizuka
1Department of Neurosurgery, Tokyo Women's Medical University, Japan. tkawamata@nij.twmu.ac.jp
Objective And Importance:
Patent foramen ovale (PFO) has been suggested as a potential source of paradoxical embolism. A higher prevalence of PFO in ischemic stroke of unexplained cause has been recognized. Brain abscesses are commonly associated with a contiguous focus of infection, hematogenous spread from a distant focus, or cranial trauma. However, no predisposing factors, including a distant focus with unknown cause, are identified in approximately 15 to 30% of reported cases.
Clinical Presentation:
We encountered two patients with brain abscess presumably caused by dental infections. Both patients displayed PFO, through which right-to-left atrial contrast shunting was revealed by transesophageal echocardiography. Although the radiological location of the abscesses suggested hematogenous spread as a cause, the patients had no arteriovenous shunting other than the PFO, despite exhaustive investigations for a potential infectious route. The patients displayed no definite focal orofacial inflammatory signs during the postoperative course despite diagnosis of pyorrhea alveolaris or periodontitis.
Intervention:
In Patient 1, the abscess was aspirated stereotactically, and in Patient 2, the abscess disappeared radiologically after high-dose antibiotic treatment.
Conclusion:
The mechanism of brain abscess formation putatively related to PFO should be different from that related to common dental sepsis. Analysis of these cases suggested that infectious embolism from a latent or even identifiable focus through the PFO may be an underrecognized cause of brain abscess, in contrast to simple seeding of the brain via transit of the infecting bacteria through the valveless emissary veins.
Insights
Patent foramen ovale (PFO) may be an underrecognized cause of brain abscesses, potentially facilitating infectious emboli from dental infections. This contrasts with typical brain abscess origins, highlighting a novel diagnostic pathway for unexplained cases.
Area of Science:
- Neurology
- Cardiology
- Infectious Diseases
Background:
- Patent foramen ovale (PFO) is linked to paradoxical embolism and cryptogenic stroke.
- Brain abscesses typically arise from contiguous infections, hematogenous spread, or trauma.
- A significant percentage of brain abscess cases lack identifiable predisposing factors.
Observation:
- Two patients presented with brain abscesses attributed to dental infections.
- Both patients had PFO with demonstrated right-to-left atrial shunting via transesophageal echocardiography.
- Despite abscess locations suggesting hematogenous spread, no arteriovenous shunting other than PFO was found, and no overt oral inflammation was present.
Findings:
- The mechanism of brain abscess formation in these cases likely differs from typical dental sepsis.
- Infectious emboli traversing a PFO from a latent dental focus may be an underrecognized cause of brain abscess.
- This mechanism is distinct from direct bacterial seeding through valveless emissary veins.
Implications:
- PFO should be considered in the differential diagnosis of brain abscesses, especially when conventional causes are absent.
- Investigating PFO may reveal a previously unrecognized source of brain abscesses originating from dental infections.
- This finding could lead to improved diagnostic strategies and patient management for cryptogenic brain abscesses.